Corneal ulcers are an ocular emergency and a leading cause of blindness globally. It is estimated that corneal opacities, including those secondary to corneal ulceration due to infections, are the fourth leading cause of blindness worldwide. The annual occurrence of corneal ulcers is roughly 1.5 to 2 million globally, with studies indicating that greater than half of the U.S. cases are due to bacteria. Common pathogens causing corneal ulcers include Staphylococcus aureus, Streptococcus pneumonia, Neisseria gonorrhoeae, Hemophilus influenza, and Pseudomonas aeruginosa. Bacterial corneal ulcers can result from inappropriate contact lens wear, trauma, and persistent corneal epithelial defects secondary to severe dry eye, neurotrophic/diabetic keratitis, and chemical damage such as chemical exposure that can occur in a military theater. Corneal ulcers can also be caused by fungi, viruses, and protozoa. In developing countries, many children with Vitamin-A deficiency are at high risk for corneal ulcers and may become permanently blind as a result.
Treatment of corneal ulcers can include antibiotics, antifungals, antivirals, and other therapeutic agents. In some cases, treatment requires applying topical medications according to an inconvenient hourly round-the-clock schedule, which may continue for multiple days. In some cases, superficial corneal ulcers can heal in less than a week. However, deeper ulcers can take longer to heal and may require additional treatments. Failure to comply with a treatment schedule can result in ineffective drug exposure, superinfections, resistant pathogens, progression of the disease, and visual degradation.